Hi Matt is right (as always!), although the filenames have changed.

(Matt, if you download the new version of FSL, you will be able to
smile at our new GUI)

The file that calls xfibres is now called
$FSLDIR/bin/bedpostx_single_slice.sh


if you look at this file, you should see the following line


${FSLDIR}/bin/xfibres\
--data=$subjdir/data_slice_$slicezp\
--mask=$subjdir/nodif_brain_mask_slice_$slicezp\
-b $subjdir/bvals -r $subjdir/bvecs\
--forcedir --logdir=$subjdir.bedpostX/diff_slices/data_slice_$slicezp\
--fudge=$fudge --nj=5000 --bi=$bi --se=100 --upe=24 --nfibres=
$nfibres > $subjdir.bedpostX/logs/log$slicezp  && echo Done


if you change --nj=5000 to 1250, and --se=100 to 25

you should have something that takes a lot less time!


Also - just to check, your Z row of bvecs should have around 30
numbers in (rather than 3)...


Cheers all

T